The output transistors can be BC548 and BC558. The circuit is from a 1975 documentation showing a frequency response from 90 Hz to 12.5 kHz.
This interesting shield circuit was obtained from a Poptronics of February 2001. The American...
This vox was found in Hughes documentation from 1968. The circuit uses components from the era. A...
This circuit shows how to use a 3-terminal voltage regulator as a low frequency oscillator by...